Method of treating oil and gas wells



Feb. 12, 1935. M. B. PITZER Er Al.

METHOD OF TREATING OIL AND GAS WELLS Filed Sept. 22, 1954 MB. B61326!" Sumo/rm Patented Feb. 12, 1935 m rso ISTATESI PATENT OFFKIE,

METHOD OF TREATING OIL AND GAS WELLS Mose B. Pitzer and Neal M. Huifaker,

, Tex.

Application September 22, 1934 Serial No. 745,140

I 4 Claims. (01.166-21) it becomes necessary not only to frequently clean out the well at the bottom but also reduce the production because of the time lost in the cleaning out operation. It is an object of the present invention to so treat the walls of the formed cavity at the bottom of the well as to prevent the material of the walls from shifting without, however, reducing the porosity of the walls.

It is a further object of in the treatment of the well, materials which will not only produce the results already stated but will serve as non-conductors of electricity so that corrosion of the well casingipr drill pipe from electrolytic action will not occur.

A further object is to employ treatment materials which'will notabsorb. or reduce the gas lime formations, it is practically impossible to maintain the cavity at a predetermined size because'the material of its walls will shift. It has been found that by using certain materials as a binder, the sand or soft lime forming the walls of the cavity can be held in place without reducing the porous nature of thecavity walls. The material used for this purpose preferably consists of bariumsulphate or barytes' crushed to 1 /2 inch mesh. Other materials such as limestone, quartz, and the like crushed to the same size may also be used under some conditions, it being essen the invention to use As before stated in all sand and in some soft tial usually that the materials employed have a specific gravity in excess of 2. 1

Of the materials which may be used barium sulphate having a specific gravity of from 4.3 to 4.8 is most desirable because it is-chemically inert and is a non-conductor of electric currents.

- After the cavity has been produced at the bottom of the well a sumcient amount'of the treatment material is deposited'in the well to fill the cavity. By means of a flat or U-shaped drill bit, the material thus deposited is pounded by dropping the tool thereon. As a result of this action the treatment material will be displaced radially and downwardly from the bit and will be forced back into the sand or soft limestone 'so as to form walls made up of an intimate mixture of treatment material and sand or limestone.

The barium sulphate or other treatment material employed will act as a binder without reducing the porosity'of the cavity walls.

Should one operation such as described be insufficient to meet the requirements, additional treatment material can be deposited in the cavity and forced back into the walls thereof as before.

Under some conditions it has been found necessary to use two or more tons of barium sulphate in order to complete the operation. Any of the treatment material which may be left free within the cavity following the completion of the operation, can be removed readily by baling it out from the well.

Should the bottom of soft, the treatment of the ,walls can .be' facilitated by covering the bottom surface with a plug of concrete. After the concrete has set the treatment material is deposited in the cavity and pounded as before described. The concrete base will prevent the material frombeing discharged downwardly into the bottom surface of the well and will, instead, deflect all of the material radially into the wall of the cavity.

After the cavity has been treated as described the well can be connected up in the usual manner and production proceeded with. It has been found in practice that by packing the treatment material back into the walls of the cavity the'sand or soft limestone formation in which the cavity is located will not crawl or become displaced; On the contrary the size of the cavity will be maintained and frequent cleaning out operations will be avoided. Consequently maximum production takes place. a

As before stated barium sulphate or'barytes is an inert substance which will not conduct elec-. tric currents. Consequently where this material the well be excessively 2 is used in the treatment of the cavity walls there will be no corrosion of metal parts such as the well casing or drill pipe, due to electrolytic action. Furthermore as the barytes will not absorb gas under pressure or react upon the gas in any way, better results are obtained than should any other material, such as iron oxide, be employed as a treatment material.

It is to be understood that the treatment material should not be smaller than 1 inch mesh.

Any finer crushed material if applied as herein stated would reduce the porosity of the cavity walls and would thus be objectionable. when the material is of the size herein used it retains the porous walls and at the same time holds the walls in shape.

In the accompanying drawing there has been illustrated the several steps in the described method.

In said drawing Figure 1 is a section through the lower portion of a drilled well prior to the enlargement of its lower end.

Figure 2 is a similar view showing a cavity which has been formed in the bottom of the well by under-reaming or by any other means.

Figure 3 shows the cavity fllledwith treatment material such as barium sulphate, prior to the pounding operation.

Figure 4 is a view similar to Figure 3 showing the treatment material after it has been pounded back into the walls and bottom of the cavity.

Figure 5 is a view similar to Figure 3 showing a modified method utilizing a bottom plug of concrete, the cavity being shown filled prior to the pounding operation.

In the drawing 1 designates the well, 2 the cavity and 3 the treatment material. A drill bit used for pounding the treatment material in order to pack it within the walls of the cavity has been indicated at 5 and in Figure 4 the treatment material has been shown commingled with the sand or soft limestone making up the original wall of the cavity. After the bit 5 has been withdrawn the packed walls will retain their shape without crawling of shifting.

In Figure 5 the concrete plug used as a support for the treatment material in the cavity has been indicated at 6, the treatment material 3 being shown within the cavity prior to being forced outwardly into the walls thereof.

The treatment material when forced into the interior of the walls in the oil and gas formation produces a porous sand or lime formation and will assure the maximum production from the oil bearing structure.

What is claimed is:

1. The herein described method of treating sand or soft limestone formations in the bottoms of oil wells and the like which includes the step of producing a cavity at the bottom of the well, filling the well with an inert treatment material of substantially 1% inch mesh, and pounding said the walls of said cavity to form an intimate mixture with the original material of the walls.

3. The herein described method of treating sand or soft limestone formations in the bottoms of oil wells and the like which includes the step of producing a cavity at the bottom of the well, filling the,well with barium sulphate of substantially 1 /2 inch mesh, and pounding said barium sulphate to displace it from the cavity and force it into the walls of said cavity to formv an intimate mixture with the original material of the walls. p

4. The method of treating sand or soft limestone formations in oil or gas wells which ineludes the steps of first producing a cavity at I the bottom of the well, thereafter forming a hard plastic coating on the bottom of the cavity, then filling the cavity above said coating with a solid treatment material of approximately 1% inch mesh, said material being inert and a non-conductor of electricity and subsequently pounding said material to displace it within the cavity and pack it into the walls of the cavity to form an intimate mixture with the original material of the walls.

MOSE B. PITLER.

NEAL M. HUFFAKER.

DISCLAIMER 1,991,293.-Mose B. Pitzer an Neal M. Haflalcer, Monahans, Tex; METHOD OF TREATING OIL AND Gas WELLs. Patent dated February 12, 1935. Disclaimer filed June 12, 1935, by the patentees.-

Hereby enter this disclaimer to allof the claims In said specification, to wit? 1. The herein described method of treating sand or soft limestone formations in the bottoms of oil wells and the like which includes the step of producing a cavity at the bottom of the well, filling the well with an inert treatment material of substantially 1% inch mesh, and pounding said material to displace it from the cavity and force it into the walls of said cavity to form an intimate mixture with the original material of thewalls.

2. The herein described method of treating-sand or soft limestone formations in the bottoms of oil wells and the like which includes the step of producing a cavity at the bottom of the well, filling the Well with an inert treatment material of substantially'U inch mesh and of a specific gravity in excess of 2, and pounding said material to displace it from the cavity and force it into the walls of saidcavity to form an intimate mixture with the original material of the walls 3. The herein'described method of treating sand or soft limestone formations in the bottoms of oil wells and the like-which includes the step-of producing a cavity at the' bottom of the well, filling the well with barium sulphate of substantially 1% inch mesh, and pounding said barium sulphate to displace it from the cavity and force it into the walls of said cavity to form an intimate mixture with the original material of the walls.

- 4. The method of treating sand or soft limestone formations in oil or gas wells which includes the steps of first producing a cavity at the bottom of the well, thereafter forming a hard plastic coating on the bottom of the cavity, then filling .the cavity above said coating with, a solid treatment material of approximately Uinch mesh, said material being inert and a non-conductor of electricity and subsequently pounding said material to displace it within the cavity and pack it into the walls of the cavity to form an intimate mixture with the original material of the walls.

[Ofiictal Gazette July 2. 1935.] 

